The Leicester City star, who scored the Three Lions' first goal from a corner, went on to say that working on set pieces during training helped his team overcome the opposition.
"We felt like we dominated the ball today, controlled the play. We were a bit too sloppy towards the end of the second half though," Maguire told reporters during England's post-match press conference.
"We knew what we'd worked on. Set plays were a big thing. The cross from Jesse [Lingard] into Dele [Alli for the second goal], we'd worked on in training, so credit to the staff and players for executing it."
England will play either Russia or Croatia in the semi-finals of the competition.